1. Field of the Invention
The present invention relates to: a method for producing a thermoplastic resin composition; a thermoplastic resin composition; and a copier/printer exterior part, and in particular relates to, for example, a method for producing a thermoplastic resin composition having high fluidity without decreasing flame resistance, impact resistance and heat resistance.
2. Description of the Related Art
Nowadays, thermoplastic resins, such as a polycarbonate resin and a polyester resin, and resin compositions thereof are widely used as molding materials for containers, packaging films, household electrical devices, OA devices, AV devices, electric/electronic parts, automobile parts and so forth in terms of their outstanding formability, mechanical physical properties, heat resistance, weather resistance, external appearance properties, hygiene, economic efficiency and so forth. Resin-molded products used therefor need to be flame retardant.
In recent years, there has been increased interest in material recycling technology for molded products made of such thermoplastic resins and resin compositions thereof because “Act on the Promotion of Sorted Garbage Collection and Recycling of Containers and Packaging (Containers and Packaging Recycling Law)”, “Act on Promotion of Procurement of Eco-Friendly Goods and Services by the State and Other Entities (Law on Promoting Green Purchasing)” and so forth were enforced in succession.
In particular, establishment of material recycling technology for PET (polyethylene terephthalate) bottles made of polyethylene terephthalate resin(s), the consumed quantity of which has been rapidly increasing, is an urgent necessity.
Also, with spread of optical recording medium products (optical disks) made of polycarbonate (PC) resin(s), such as CD, CD-R, DVD and MD, there have been examined a method for recycling bits and pieces generated when these products are formed and a method for recycling polycarbonate resin(s) obtained from waste optical disks after their reflecting layers, recording layers and so forth are removed.
When crystalline polyester resin(s) represented by PET resin of, for example, used PET bottles collected from the market or resin(s) obtained by pulverizing molded products made of PC resin, such as optical disks, is molded again by, in particular, injection molding, the resin needs to have high fluidity in molding as a resin property so as to be used for various molded products.
These days, large products in particular have been examined to meet a demand for being thin and flame retardant, and as the large products become thin, they need to be heat resistant to bear thermal deformation.
Further, when a resin composition contains a polyester resin and a polycarbonate resin for components of household electrical devices, OA devices (copiers and printers) and so forth, the resin composition needs to have high impact strength.
Polycarbonate resin(s) is outstanding in flame resistance, impact resistance, heat resistance and so forth, but low in fluidity and accordingly poor in formability. Therefore, polycarbonate resin(s) cannot be used for various molded products.
Then, various attempts have been made to increase fluidity of polycarbonate. For example, there has been proposed a method for polymer-alloying of a polycarbonate resin and an ABS resin or the like. (Refer to, for example, Japanese Patent Application Publication No. H11-293102.) However, such conventional polymer-alloying of a polycarbonate resin and an ABS resin or the like greatly decreases heat resistance temperature and cannot achieve high impact strength (impact resistance) and high flame resistance although it increases fluidity.